Senator Barbara Boxer (D-CA), Chairman of the Environment and Public Works Committee and a vocal critic of Edison's handling of the plant, said in a statement she was "relieved" that the plant would be closed permanently:

"I am greatly relieved that the San Onofre nuclear plant will be closed permanently. This nuclear plant had a defective redesign and could no longer operate as intended. Modifications to the San Onofre nuclear plant were unsafe and posed a danger to the eight million people living within 50 miles of the plant. After a leak of radiation from the steam generator tubes, I became increasingly alarmed that Southern California Edison had misled regulators by minimizing the scope of the changes made at the nuclear plant to avoid a full safety review and public hearings. That is why I have asked the U.S. Department of Justice, as well as the California Public Utility Commission and the Nuclear Regulatory Commission, to investigate. I want to thank the community organizations that came forward with information which demonstrated that the plant redesign presented a great risk to the public. Now that the San Onofre nuclear plant will be permanently shut down, it is essential that this nuclear plant be safely decommissioned and does not become a continuing liability for the community."

Boxer told KPCC that she wants the Department of Justice to find out whether Southern California Edison deliberately misled regulators. She says she's seen the documents.

"They essentially averted and avoided a full license review," she said. She added that the Justice Department conducted a similar review of British Petroleum after Hurricane Katrina, finding "absolutely" there was criminality. She says she's "very concerned" that regulators were misled.

The next battle, she says, is making sure the decommissioning is done right. "I want to make sure it's done safely, I want to make sure that there are no corners cut, I wanna make sure that the plant not an eyesore."

Boxer wants to make sure ratepayers aren't left picking up the tab for the shut down of San Onofre. She says the California Public Utilities Commission understands this.

Gov. Jerry Brown issued his own statement regarding the decision:

"Since San Onofre nuclear power plant went offline last year, energy utilities and the state have worked to provide Southern California with reliable electric power year round. At my direction, California's top energy experts will continue developing a long-term plan that ensures there is reliability for decades to come. As we move into the hot summer months, we can all do our part by continuing to conserve."

The Nuclear Regulatory Commission will be the lead agency overseeing that process. NRC spokesman Scott Burnell says Edison first must notify regulators that it's permanently removed all fuel from San Onofre's reactor cores. "Until that occurs, the NRC will continue its oversight of the plant to ensure it meets all applicable requirements." Burnell says regulators want to see the utility's formal proposal to permanently close the plant before making any decisions on the ongoing investigations.

"It is all over now, citizen advocates for safety rejoice," read an email from the San Clemente group Residents Organized for a Safe Environment (ROSE).

"I'm elated that SCE made such a good decision for the quality of life for all of Southern California," said ROSE founder Gene Stone in an interview with KPCC.

But after Stone celebrated the closure, he turned to the future.

"I have real concerns about how we go ahead with the decommissioning," Stone said. "Unit 1 (previously retired) is buried on site, will they have room to bury Unit #2 and Unit #3 on site? It’s not permitted as a nuclear storage facility. But at least it’s no longer producing nuclear fuel."

The U.S. has not created a permanent storage facility for spent nuclear fuel.

“No one signed on to have nuclear waste stored on our coast,” said Stone.

Does the closure of the San Onofre plant — following the shutdown of plants in Florida and Wisconsin this year — signal a tipping point for the nuclear power industry?

"There are two reactors still operating in California, and the two at San Onofre bring the total to, I think, ... five that have previously shut down," said David Lochbaum, a nuclear engineer who once worked for the Nuclear Regulatory Commission and who is currently the director of the nuclear safety program for the Union of Concerned Scientists.

The timing of the rash of closures is due to the economics of aging plants and the challenge of replacing or upgrading them safely. And there may be more to come.

Still, California is expected to remain reliant on nuclear power, Lochbaum said. "The largest nuclear power plant in the US is in Arizona, and California imports some of its electricity from Arizona, including some from that plant, so California will continue to import nuclear electricity for the foreseeable future," he said.

For its part, Mitsubishi Heavy Industries — which produced the equipment that led to problems in one of the reactors at San Onofre — expressed disappointment at Southern California Edison's decision to close the plant.

"We've continued to work closely with SCE to address all technical matters necessary to safely re-power SONGS (San Onofre Nuclear Generating Station) since the issues at SONGS were first detected,. We remain confident that SONGS could be operated safely and reliably. We understand, however, the complex and challenging factors which may have driven this decision."

The environmental activist group Friends of the Earth, has been fighting for years to get San Onofre shut down.

"People in Southern California have been living with these dangerous reactors built in a very unsafe place for decades and they can really breathe a sigh of relief," said Damon Moglen with Friends of the Earth.

Carlsbad anti-nuclear activist Ace Hoffman was happy to hear the plant would be shutdown permanently but worried about storage of spent nuclear fuel.

"Unfortunately we are now left with one of the largest, most concentrated nuclear waste piles on the planet," said Hoffman. "This will be an eternal problem, but thankfully it is no longer a growing problem and is becoming safer by the day. It will take millions of years — not just days — to be safe, but at least we are headed in the right direction."

The California Public Utilities Commission’s (CPUC) President, Michael R. Peevey, said Friday the agency plans to move quickly in deciding who should bear the costs for the 16-month shutdown of the nuclear plant.

"The CPUC acted quickly last year to open an investigation into the outage, protecting ratepayers from unreasonable costs. We urge the various parties in the CPUC’s proceeding – ratepayer representatives, environmental advocates, the utility itself, and others – to meet and discuss a joint proposal for permanent shutdown. Such a settlement would then be brought to the CPUC for ultimate disposition, and potentially avoid a protracted litigation that could delay refunds to ratepayers and extend uncertainty for electric system planners."

Gregory Jaczko, who chaired the Nuclear Regulatory Commission (NRC) from 2009 to 2012, said Tuesday that U.S. regulators no do not pay enough attention to the dire consequences of nuclear accidents. He spoke in San Diego at a June 4 meeting on the future of nuclear energy.

“When I was at NRC, there was resistance to looking significantly at these things,” said Jaczko. “I think that’s a mistake.”

Jackzo said most U.S. nuclear plants were designed 50 to 60 years ago and have antiquated safety measures.

According to Edison, the costs for the outage, retirement and decommissioning of the San Onofre nuclear plant will come from four sources.

The Natural Resources Defense Council's Legal Director for Western Energy and Climate Projects, Kristin Eberhard, issued the following statement:

“SoCal Edison realizes we have better energy options than nuclear and it's futile to pump money into an outdated technology.

“Instead of putting Band-Aids on a nuclear plant built decades ago, the company decided to better serve its customers and its shareholders by moving forward with a portfolio dominated by energy efficiency and other clean energy solutions.

“Other energy providers also struggling with aging and outmoded nuclear plants elsewhere can learn from SoCal Edison, and listen to what the majority of Americans say they want: less costly, better, safer, more modern options to nuclear.”